Method of impregnating materials



April 16, 1935. J. E, SHEPHERD El AL 1,998,100

METHOD OF I MPREGNATING MATERIALS Filed July 14, 1928 3 25727202245 Jr/k ATTORNEY Patented Apr. 16, 1935 UNITED STATES PATENT, OFFICE METHOD OF IMPREGNATING MATERIALS John E. Shepherd and Raymond D. York, Charlottesville,Va., assignors to National Cold Steam Company, Charlottesville, Va., a corporation of Delaware Application July 14, 1928, Serial No. 292,722

8 Claims. (CI. 99-12 Our present invention relates to an apparatus high pressure and temperature for, and at, the for, and method of, impregnating materials with pressures and temperatures hereinafter set forth protective, preservative fluids, and more parin our preferred, herein, embodiment to be a full ticularly to methods of impregnating construcequivalent of the herein disclosure and method.

tion or other materials with protective substances Further, we have found that when such a blast 5 against all forms of attack, weather, pest proofis applied to the surface of. a material being ing, as the case may be, through the medium treated, that the heat of the blast stimulates the of a vaporized fluid applied thereto under prescapillary action of the material which creates an sure. expansion of the pores or cells permitting ready 1Q Impregnation of materials with protective liqt e of t impregnating Substances, and 10 uids has been done by a variety of methods. h n, reinf d y h pressure in h pply Among these, the tank, immersion and vacuum stream, the impregnating liquid is forced deep chamber methods have been most generally used. into the substratum of the material.

One of the grave disadvantages in these methods It will be obvious that such a method lends is the fact that materials to be treated must be itself to economical and efficient use. The pre- 15 transported to the impregnating plant, due to ferred apparatus for carrying out our method the bulk and non-portability of the latter. being portable, it becomes easy to impregnate Another inherent disadvantage of these presmaterials erected in a construction pr j ent known methods is the limited use to which parts of trees and other uses to be later described.

they can be put. For instance, stone in a build- Accordingly, one of the main objects of our 20 ing, parts of trees, or timber erected in a coninvention is to provide an apparatus for, and a struction project can hardly be impregnated by method of, impregnating materials with prothese methods since, in treating, it is not practective substances, which method is flexible in tical to remove them from their positions and use, the apparatus being portable, a blast of hot thereafter replace them. Again, the tank impressure fluid being utilized to force the protec- 25 mersion, vacuum chamber, or other impregnation tive substances into the substratum of the mamethods, cannot economically be used to impregterial being treated. nate with protective substances certain materials Another object is to provide a method of such as stone, brick and the like. weatherproofing, waterproofing, sterilizing and m We have discovered and applied a method of preserving materials of diverse nature by impregeconomically impregnating porous or cellular manating them with substances possessing such terials such as stone, brick, stucco, wood, tile, above noted properties, which substances are inartificial stone and other materials, with protecjected into the materials by hot pressure fluid. tive substances, regardless of where they may be Another object is to provide a method of, and

5 located or erected. For example, our method apparatus for, cleaning, preheating and sterilends itself as easily to treating exposed timber lizing material infested with decay-causing pests, in a pier, building or the like, erected posts, fences 'by subjecting the materials to a blast of steam or telegraph poles, bridges or the like in situ, as it or hot air under pressure, the same carrying sterdoes to the components thereof during manufacilizing substances, thus destroying germ and ture. fungi-encouraging conditions, insects and insect 40 Fundamentally, our method takes advantage of larvae. the increased capillary action of materials when Another object of our invention is to treat masubieeted o a hi h degree of heat, and the fact terials subject to decay-causing organisms and that flu d under h pressure can be forced moisture which comprises the steam cleaning of into the heated substratum of the hardest mate- Such materials and the impregnation of such 5 We hfwe also found P w a heated liq; materials with weather or waterproofing and i pmtectlvsubsiance 1S SubJected to blaist toxic substances, thereby eliminating the-future of hotpressme fluld' 51.1611 as Stfmm or .1101; development of such deleterious factors. that the substance lS effectively dispersed A th t f t t throughout the blast zone in a physical state no er 0 380 0 our mvefn Ion 0 we the surfaces and substrata of materials, such as between that of a colloid and a suspension.

Due to the use of a heated pressure fluid stone and wood, to weatherproofing substances,

tre m, carrying th t m herein sp ifi d thereby enabling the materials to repel moisture singly or in combination, as above noted, we reand prevent Suc moisture from entering the gard the substitution of a stream f air, nd r materials from the exterior or weather surfaces thereof, thereby to preserve said surfaces from a too rapid deterioration.

Another object of the invention is to provide an apparatus and method to accomplish the aforedescribed objects and to have means assooiated therewith, whereby a hot pressure fluid, at normal steam or superheated temperatures, toxic substances, waterproofing and weatherproofing materials, and fireproofing, cleaning or coloring substances may be selectively ejected therefrom independently or jointly by the operator.

Other objects of the invention are to improve generally the simplicity and efficiency of such devices and to provide a device which is economical, durable and reliable in use and economical to manufacture.

Many of the features of the invention may be used without employing all of them, as some of those which are non-essential may be omitted without departing from the spirit of the invention, though such omission may, to a greater or less extent, aifect the quality of the result.

Moreover, the apparatus for accomplishing the methods of this invention is capable of receiving various mechanical expressions without departing from the spirit of the invention itself; and, for the purpose of describing the invention, there is illustrated in the accompanying drawing, the preferred form of apparatus in which:

Fig. l is a diagrammatic view of the apparatus used to accomplish the method.

Fig. 2 illustrates one form of a material educing spray nozzle in section.

Referring more specifically to the drawing, a wheeled truck comprising a base I, carried on wheels 2, supports thereon a conventional vertical steam boiler 3. This manner of mounting the apparatus insures portability and ease of transportation of the apparatus from place to place during-use. Thus, when treating material, such as ties, telegraph poles, bridge timbers, etc., in situ, considerable transporting and handling charges are saved, as the apparatus may be brought to the location instead of the treated material being carted to and fro.

A steam line 4, valved as at 5, leads from the boiler 3 to a pressure fluid applying nozzle 6. Steam is preferably generated in the boiler at about lbs. pressure and at about 358 degrees Fahrenheit. Obviously, other temperatures and pressures may be used. At the stated pressures and temperature however, optimum results are obtainable.

Spaced from, and enclosing the steam line 4, there is arranged a duct 8 which is adapted to carry the various liquid impregnating materials, singly, or in combination. The steam line 4 and the enclosing material conducting duct 8 are made of suitable flexible hose material and are joined by a suitable steam and liquid tight coupling 22 at said point. Thus, between these points 22 and 6, the hose comprises an inner tubing 4 to carry the hot pressure fluid, and an outer material carrying tubing 8 concentric therewith for carrying the impregnating substances. It will be observed that the substances flowing through line 8 are constantly maintained in a hot condition by transfer of heat, by contact, from the hot pressure fluid flowing through the inner steam line 4.

Three material holding and treating tanks 9, l0 and II are mounted on the truck base I. Tank 3 may contain a waxy or oily substance which has waterproofing, weatherproofing and non-oxidizing properties, and which is readily absorbed by materials to be impregnated. Such a material may have moisture repelling qualities. Among many materials which are suitable in this respect is parafiin wax, paraflin oil, aluminum stearate, thick oils, waxes, petroleum bases containing slight amounts of aluminum stearate, fish oils and other oils of like nature.

A steam heating coil I5, leading from the boiler connection 30, valve controlled at l5, and disposed in tank 9 supplies sufiicient heat to the contents thereof to maintain it hot and in liquid condition for application.

In tank l0 there may be placed a toxic material. We use toxic in the broad sense of the word, that is to say, a material detrimental and fatal to bacteria, insects, fungi, and all similar parasitic and destructive organisms. Materials of this nature are toxic arsenic compounds as arsenate of calcium, lead, soda, zinc or the arsenites of these metals; toxic copper compounds as Paris green and Bordeaux'mixture; lime; sulfur and lime sulfur combinations; zinc chloride, boric acid. nicotine-sulfate solutions; toxic aniline dyes or other toxic substances or solutions that have insecticidal, germicidal and fungicidal value.

Preferably, these materials should be in liquid condition in the tank, and may be used singly or in combination. Their use depends, at any time, on the material being treated and the pest to be destroyed. This applies as well to any material in tank 9.

A steam coil l6 leads from boiler connection 30, valved at l6, into the tank Ill and maintains the contents thereof in a hot and liquid state for application.

The tank ll may carry a fireproofing, cleaning substance, or coloring dye, depending on the use to which the apparatus is to be put. In this tank, also, there is a steam coil 3|, tapped from line 30, under control of valve 3|. The coils l5, I6 and 3| have a common blowoff 32, valved as at 33, to maintain circulation of steam therein. Obviously, as many tanks as desired may be used in accordance wit. the types and kinds of materials to be utilized.

A steam line I! leads from the boiler 3 and has three valved branches l8 tapped therefrom and leading into each one of the tanks 9, Ill and II. The purpose of these branch connections is to place the material in the tanks under discharge pressure whereby to insure positive flow of material therefrom to the nozzle 6.

Each tank is further supplied with a removable clamped-on cover 34, having means 35 between the covers and tanks so clampably hold the covers on in leakproof manner, and to permit filling with treating materials and solutions.

Each tank is tapped at its bottom by a valved discharge duct l2 leading to the nozzle duct 8, and controlled by a hand valve l2. A valved by-pass l9 taps the line 8 near the nozzle 6, and guides the impregnating material flowing through feed pipe 8 into the eduction chamber 20 of the nozzle, Fig. 2. Operation of the valve l9 feeds or cuts off material to the nozzle 6, as desired.

The pressure fluid, flowing from duct 4 into the nozzle 1, due to its expansion in passing out of nozzle 4, draws material from duct 8 into eduction chamber I by induction, and, plus the pressure of the boiler upon the materials within the tanks, the materials are ejected from nozzle 6 in an intimately mixed atomized jet of high velocity and temperature. A hand valve 39, associated with nozzle 6, controls the supply of steam (pressure fluid) from duct 4, thus giving local control of steam supply at the nozzle position.

In the treatment of wood and some forms of stone it,is sometimes desirable to superheat the steam supply to the duct 4, and to this end we have provided a superheating coil 48, located within the fire box of the boiler, the fire box being indicated by the dotted lines 49. Hand valves 4|50 control the coil so as to by-pass steam from duct 4, by opening valve 41, and closing valve 50. When this is done, all steam from the boiler 3 passes through coil 48 to nozzle 6 and becomes superheated.

Further, we also provide for a supply of superheated, compressed air, which may be mixed with the steam supply in duct 4, this mixture being also passed to the nozzle 6. Thus, by the structure now to be described, a stream of hot air is injected into pipe 4. On the truck base I there is disposed, against the boiler 3, a steam engine driven compressor 43 of conventional design. The rear view, more or less diagrammatic of the air and steam cylinders is shown, since this type of means is well known. A pipe 42, valved as at 43, taps the common compressor discharge pipe 4| of the air cylinders 40 of the compressor.

The pipe 42 passes air from the compressor into the superheater coil 44, shown in dotted lines. An external connection 45 joints the coil 44 with the main steam line 4. Thus, the compressed air issuing from line 45 is superheated and flows through line 4 as a hot gas under high pressure and admixes with the steam flow to the nozzle 6. Thus, hot pressure fluid is ejected from the nozzle,

A the hot pressure fluid serving not only to forcibly educe materials in line 8 from the nozzle, but to maintain the latter materials in fluid condition, when required, and ready for application and impregnation.

It is possible, also, to change our apparatus into a superheated air device for the herein purposes, without the use of steam as a direct means for impregnating. For instance, valves l8 may be opened, admitting steam pressure upon the tank contents. Valves i5, i6 and 3| may be opened, also drain valve 33, and cause controlled coil heating of the tank contents. Then with valve 5 closed shutting off the steam from duct 4 and, possibly, closing valve 41, the running of the compressor 40-40 passing the compressed air therefrom to and through coil 44, with valve 43 opened, superheated compressed air alone is passed through coil 44, duct 4 to nozzle 6, there to perform in a manner similar to that described for.

the steam impregnation of maifierials indicated.

We will now describe the manner of use ofithe apparatus disclosed above, and the various applications that the method lends itself to, with the understanding that many other uses and applications are possible. Assuming that exposed wooden piles, normally subject to the action of borers, dry rot and fungus decay, are to be treated, our method consists in first cleaning the wood thoroughly by means of a blast of steam or superheated hot air. In some cases the steam cleaning thus described may be eliminated, such as, for instance, in the treatment of new wood.

For steam cleaning, the valves on pipes l2 are all closed thus cutting off liquid impregnating supply from the tanks 9, l0 and H, from duct 4. Valve I9 is kept closed at all times except when line 8 is actually delivering material. The valve 39 is opened and a blast of high pressure steam at normal or superheated temperatures is played over the wood being treated. This results in a literal scalding and sterilizing of all the growth and organisms on the surface of the wood. An-

other result of this preliminary heat treatment is that the cells, fibres, vessels, ducts and pores of Wood are made pregnable for the subsequent reception of impregnating materials.

The valve or valves I! are then opened and the materials from any or all of tanks 9, l0 and H are passed into duct 8, and thence to nozzle 6, such materials being heated during transit by the steam passing in duct 4. Thus if the wood is to be first impregnated with toxins, then the outlet valve associated with tanks I0 is opened, permitting the particular toxin in tank ID to flow through line 8 to the nozzle 6.

Again, if a mixed stream of paraflin, toxins and fireproofing material is to be used,,then all the outlet valves associated with tanks 8, l0 and H would be opened. The valves I9 and 39 at the nozzle 6 are manipulated to allow the combined stream of hot pressure fluid and impregnating liquids to be ejected.

When the hot stream under pressure strikes the surface of the material being treated, the contents of the pores, cells, fibres, vessels and ducts, if any, is displaced by the vapor under forced pressure. The vapor condenses in the pores and cells of the material, thus filling them with condensed waterproofing, toxic and fireproofing materials.

It should be noted that the impregnating material rendered molten and liquid, and ejected into the blast of hot pressure fluid in the mixing nozzle, issues therefrom in a phase which is between the colloidal state and a suspension. In other words, an efficient and thorough impregnation of the woodoccurs because the impregnating materials are atomized intominute particles, and forced into the wood under high pressure, thus filling the substratum of the wood with the protective material.

Another fact is to be noted. The pressure fluid at 385 degrees Fahrenheit is hot enough to stimulate and induce a maximum of capillary action in the wood, when it strikes the same. In fact, we attribute the successful operation of our method, and deep impregnation secured thereby, to the combined action of the capillary action in the material being treated induced by the heat of the pressure fluid, and the great forceexerted by the latter upon the particles of the impregnating substances dispersed throughout the pressure fluid.

Hot compressed air can be used as readily as steam in the above application of our method, and the materials that may be impregnated by our herein disclosed method are numerous. For instance, we have impregnated sandstone, hard pine, Celotex, concrete, porous stones such as chalk, lime, wood materials as compressed artificial lumber and board, brick, stone, stucco, mortar, unglazed tile and various other manufactured or natural construction or building materials.

In every one of these cases, the degree of penetration depends on the pressure of the pressure fluid, the temperature of the fluid, the porosity of the material being treated and the nature of the impregnating materials used. But the best results are obtained at the pressure fluid temperature given above. Wood, stone and artificial composite board are impregnated by our method in quicker time, with less expense and to a greater extent than with the tank immersion method of impregnation. Further," such penetration is done without recourse to an air lock or closed receptacle.

. delivering nozzle, consisting The above method allows the use of stone as a veneer to buildings much thinner than is used in present practice. Consequently, building costs may be cut, and stone used half as thick as is used at present, or even thinner. Stone treated by our method, after a half hour or so of blast treatment shows as much as a quarter to a half of an inch of impregnation. This impregnation is so thorough and deep seated that the stone enclosed within its protective bounds is preserved for long periods of time.

The portability of this method enables it to be effectively used in combating the ravages of pests on railroad ties, telegraph poles, bridge timber, piles and other construction materials in situ, in locations infested with destructive and decaypromoting organisms and growths.

Another use to which our method is adapted for is in agricultural developments. For example, tree wounds due to removal of large limbs, or to injury from any cause, as by rabbits, mice, plows etc., around the base of trees can be promptly sterilized and impregnated with the waterproof, weatherproof and sterilizing materials. Thus, attack by fungi, or wood boring insects is effectively countered.

Again, frequently decayed cavities in the trunks and limbs of trees are infested with wood boring larvae. or are the retreat of different species of ants. Such cavities are objectionable, for not only do they favor gradual decay and weakening of the trees, but they afford an excellent winter harbor for such insects as the codling moth. In such cases the rotten sections of trees are steamed out and removing mechanically, in some cases, the rotted wood as far as is necessary. The remaining cavity or diseased parts are then sterilized and the poisoned parafiin materials injected into the parts to arrest further rot and protect it from the weather and the insects.

Thus, it is apparent that our present method and apparatus are applicable to a multitude of uses, some in construction materials in situ, others in agricultural fields, and still others in numerous ways that will readily suggest themselves to those using the method.

We claim:

1. A method of impregnating which consists in subjecting the exterior surface of a material, such as stone and wood, to heat, and simultaneously forcing a substance having toxic, weatherproofing and waterproofing properties into the sub-strata of said material, said substance being dispersed throughout and applied directly to said surface by a blast of hot vapor.

2. The process of treating an exposed surface of construction material in situ for waterproofing, preservative and fireproofing purposes, which consists in directly projecting against such an exposed surface a blast of highly heated gas under high pressure, and simultaneously feeding substances to accomplish said purposes into said blast whereby the combined action of the blast pressure and the increased capillary action of the material result in thorough impregnation of the sub-strata of the material with such substances.

3. A method of waterproofing a stone wall with an apparatus which includes a movable steam in directing the nozzle against one part of said wall to heat the substratum of said part, mixing waterproofing material with the steam during its delivery to impregnate the heated substratum, and moving said nozzle with its steam and waterproofing material over the other parts of said wall.

4. A process of impregnating wooden and stone structures, said process comprising applying to said structure a high pressure dynamic superheated blast of hot fluid, paraffin, toxins and fireproofing materials, whereby said materials are finely atomized and mixed and said mixture is highly heated, liquefied and disrupted; and directing said blast upon said structure, whereby said structure is highly heated thereby to render the structure absorbent to the highly heated materials, and whereby said materials are tamped by the dynamic stream into said structure and absorbed into the pores of the hot structure.

5. A process of impregnating building struc tures with preservatives, said process comprising applying to such structure a high pressure dynamic blast superheated to about 385 F., consisting of a mixture of steam, molten paraflin, toxin and fire-proofing materials whereby said materials are mixed, highly heated, liquefied and disrupted by the released latent heat of the steam and finely atomized to a state intermediate between colloidal and suspension and rendered absorbable into the pores of the structure; and directing said blast upon said structure, whereby said structure is highly heated by further released latent heat of the steam thereby to render the structure absorbent to the highly heated materials, and whereby said materials are tamped by the dynamic stream into said structure and drawn into the pores of the structure by the condensation of said stream.

6. A process of impregnating wooden and stone structures, said process comprising applying to said structure a high pressure dynamic blast of superheated gaseous fluid, substantially free of other materials; then introducing into said blast, a heated impregnating material absorbable in the pores of the structure; and directing said blast upon said structure, whereby said structure is further highly heated thereby to render the structure absorbent to the highly heated material, and whereby said material is tamped by the dynamic stream into said structure and absorbed into the pores of the hot structure.

7. A process of impregnating wooden and stone structures, said process comprising applying to such structure a high pressure dynamic blast of superheated gaseous fluid at about 385 F., substantially free of other materials, applying said blast alone sufliciently long to clean the structure, sterilize living organisms therein, to heat the structure sufliciently to render the capillaries and pores of the structure pregnable to subsequent impregnating materials; then introducing into said blast by induction of the blast, substantially at the point of liberation, heated molten paraffin, whereby said paraflin is highly heated, liquefied and disrupted and finely atomized to a state intermediate between colloidal and suspension and rendered absorbable into the pores -of the structure; and directing said blast upon said structure, whereby said structure is further heated to render the structure absorbent to the highly heated materials, and whereby said materials are tamped by the dynamic stream into said structure.

8. A process of impregnating, with preservatives, unenclosed large wooden structures in situ, said process comprising applying to said structure a high pressure dynamic blast of superheated steam at about 385 F. substantially free of other materials and having latent heat therein, applying said blast alone suificiently long to clean the structure, sterilize living organisms therein, to render the cells, fibers, vessels, ducts, pores and capillaries of the structure pregnable to subsequent impregnating materials and to fill the pores with steam; then introducing into said blast by induction of the blast, substantially at the point of liberation of the blast, a heated molten mixture of paramn, toxins and fireproofing materials whereby said materials are mixed, highly heated, liquefied and disrupted by the released latent heat of the steam and finely atomized to a state intermediate between colloidal and suspension and rendered absorbable into the pores of the structure; and directing said blast upon said structure, whereby said structure is highly heated by further released latent heat of the steam thereby to render the structure further absorbent to the highly heated materials, and whereby said materials are tamped by the dynamic stream into said structure and drawn into the pores and capillaries of the structure by the partial vacuum therein caused by the 10 condensation of said steam therein.

JOHN E. SHEPHERD. RAYMOND D. YORK. 

